In hydrocarbon recovery operations in subterranean wells, it is often necessary or desirable to clean debris from one or more surface or area of the well or component(s) in the well. For example, after a casing is perforated, it is typically desirable to remove perforating burrs and other debris from inside the casing or liner prior to the installation of completion equipment.
However, various presently known tools and techniques for cleaning underground surfaces or areas are believed to have one or more drawbacks. For one potential example, when an obstruction is detected in the well during drifting of the casing, the drift sub or other tool often needs to be entirely removed from the well to allow insertion of a suitable cleaning tool, such as a convention mill. This process requires an additional round trip into the well. For another example, some existing tools are believed to be limited to performing cleaning during rotation, which may be undesirable or impossible when there are torque related problems or other limiting conditions. In some instances, existing cleaning technology may not be capable of providing full coverage in deviated or horizontal wells. Some existing tools may also, or instead, be ineffective at accommodating turbulent fluid flow or directing debris upwardly for disposal. Various known cleaning tools having milling ribs are believed to be unable to provide full coverage of the inner diameter of the item to be cleaned, ineffective at transmitting rotational torque to the tool body, or not fully retractable (beyond the outer diameter of the tool or other components) when deactivated. For yet other examples, known tools may include externally exposed connectors or components that can become dislodged and cause problems in the casing or well bore, not allow unrestricted fluid flow through the tool after deactivation or include deactivation mechanisms that could bind up or malfunction.
It should be understood that the above-described discussion is provided for illustrative purposes only and is not intended to limit the scope or subject matter of the appended claims or those of any related patent application or patent. Thus, none of the appended claims or claims of any related patent application or patent should be limited by the above discussion or required to address, include or exclude each or any particular of the above-cited examples, features and/or disadvantages merely because of their mention above.
Accordingly, there exists a need for improved systems, apparatus and methods capable of cleaning an underground surface or area in a subterranean well and having one or more of the attributes, capabilities or features described below or evident from the appended drawings.